Who? Who wrote the information?
When? When was it published?
Where? Where was it published?
What? What is the information really about?
Why? Why did they write information?
How? How did they get their information?
These factors may not apply to every situation equally. For example: an older scholarly journal article may not be appropriate for a paper on current controversies, but it could be relevant to a historical approach to the topic. Use your best judgment, and ask a librarian if you’re sure about a source.